Conventionally, there is a method wherein a camera is attached to a movable body, such as a vehicle, surrounding images including a road surface are captured, and the movement amount of the vehicle serving as the movable body is measured from the movement amount of a pattern on the road surface. Such a technique has been disclosed in Shuhei Takimoto and Takaaki Ito, “Development of 3D Scene Analysis System Using In-vehicle Camera”, SEI TECHNICAL REVIEW, No. 169, P. 82-P. 87, July 2006.